http://blogs.msdn.com/tom/archive/tags/Threading/default.aspxTags: Threadingen-USCommunityServer 2.1 SP1 (Build: 61025.2)http://blogs.msdn.com/tom/archive/2008/01/21/j-threads-calling-gc-collect.aspxMon, 21 Jan 2008 22:53:28 GMT91d46819-8472-40ad-a661-2c78acb4018c:7187545Tom0http://blogs.msdn.com/tom/comments/7187545.aspxhttp://blogs.msdn.com/tom/commentrss.aspx?PostID=7187545http://blogs.msdn.com/tom/rsscomments.aspx?PostID=7187545<h3>Problem</h3> <p>We have had a few customers run into this issue where they are using the J# ThreadEnd objects and see problems with the GC running a lot.&#160; If you look at the actual callstack that is calling the GC, it will be the finalizer thread cleaning up this ThreadEnd as we see here:</p> <p></p> <pre class="debug">0:036&gt; k Child-SP RetAddr Call Site 05cef478 00000000`1bf31dc5 mscorwks!GCInterface::CollectGeneration 05cef480 00000642`7f66bdc6 vjslib_ni!com.ms.vjsharp.lang.ThreadEnd.Finalize()+0x35 05cef4e0 00000642`7f4ebf2b mscorwks!FastCallFinalizeWorker+0x6 05cef510 00000642`7f4ec075 mscorwks!FastCallFinalize+0xbb 05cef590 00000642`7f4f16e2 mscorwks!MethodTable::CallFinalizer+0x69 05cef5e0 00000642`7f4f1524 mscorwks!SVR::CallFinalizer+0x72 05cef640 00000642`7f4f146b mscorwks!SVR::DoOneFinalization+0x84 05cef700 00000642`7f61fb1b mscorwks!SVR::FinalizeAllObjects+0x9b 05cef7c0 00000642`7f5264cc mscorwks!SVR::FinalizeAllObjects_Wrapper+0x1b 05cef7f0 00000642`7f52693d mscorwks!ManagedThreadBase_DispatchMiddle+0x12c 05cef900 00000642`7f608455 mscorwks!ManagedThreadBase_DispatchOuter+0x31 05cef940 00000642`7f4a71bc mscorwks!ManagedThreadBase_DispatchInCorrectAD+0x15 05cef970 00000642`7f44b939 mscorwks!Thread::DoADCallBack+0xd0 05cefab0 00000642`7f4f15f6 mscorwks!ManagedThreadBase_DispatchInner+0x51 05cefb00 00000642`7f4f146b mscorwks!SVR::DoOneFinalization+0x156 05cefbc0 00000642`7f4b679d mscorwks!SVR::FinalizeAllObjects+0x9b 05cefc80 00000642`7f5264cc mscorwks!SVR::GCHeap::FinalizerThreadWorker+0xbd 05cefcc0 00000642`7f52693d mscorwks!ManagedThreadBase_DispatchMiddle+0x12c 05cefdd0 00000642`7f463c36 mscorwks!ManagedThreadBase_DispatchOuter+0x31 05cefe10 00000642`7f4b6d64 mscorwks!ManagedThreadBase_NoADTransition+0x42</pre> <p></p> <p>From this we can see that the Finalize method of ThreadEnd is calling the collection.&#160; This is something that these threads do.</p> <h3>Workaround</h3> <p>The only way around this, if this is causing a problem, is to switch from using Java threads to .NET Threads instead as they don't call GC.Collect().</p> <p>This problem has been mentioned a few times, including on <a href="http://blogs.msdn.com/maoni/archive/2004/06/03/148029.aspx">Maoni's blog</a></p><img src="http://blogs.msdn.com/aggbug.aspx?PostID=7187545" width="1" height="1">DebuggingThreading